I just had this theory that since some humans are colorblind, maybe it's just a ratio across different species of animals and humans happen to have a much higher ratio of those that can see in color versus those that cannot. I'm thinking that a certain breed of dog or a certain percentage can see in color while others cannot. This could be universal across most species of animals that use an occular system similar to that of humans. What do you think? After a quick google search there were some tests done to prove that some dogs could see in blue or green colortones as well as black and white, well that leaves the question of whether or not they can see in an entirely full color spectrum or if dogs can see light in the same way that humans do.